Applications of Laser

Introduction To Laser

The laser is a light emitting device that emits light based on the concept of Stimulated radiation. Lasers are controlled light source. The word laser acronym for Light Amplification by Stimulated Emission of Radiation. Laser lights differ from the ordinary light beam.

Ordinary light is not monochromatic. It is incoherent i.e., there is a wide phase difference between the light observed at a point at different times and at different points in space.

The laser beam is highly monochromatic and highly coherent with all the waves exactly in phase with each other and in the same state of polarization. Directionality, monochromacity, intensity, and coherence are the peculiar properties of the laser beam.

Einstein predicted in 1917 that there must be a second emission process to establish thermodynamic equilibrium. He is called this second type emission as stimulated emission. lasers works on the principle of stimulated emission.

The important features of stimulated emission are:

The process of emission is controlled from outside.

The Photons emitted in this process propagated in the same direction as that of the stimulating photon.

The emitted photons have exactly the same phase, frequency, and plane of polarization as those of the incident photon.

The light produced in this process is directional, coherent and monochromatic.